Unsticking Valves & Pistons

Unsticking Valves

Subject: Stuck Valves
Date: Fri, 24 Nov 2000 19:23:00 -0600
From: "Charles r. Bryant" 

Unsticking Pistons

Subject: Sattley 1½ HP Restoration Status
Date: Sat, 23 Sep 2000 19:19:12 EDT
From: FRM8198@aol.com

Hi List,

The use of transmission fluid was a success as a penetration oil. The engine was positioned in the vertical position (head up) and cylinder was fill with transmission fluid. Then, grease was injected into the cylinder via the spark plug hole which was fitted with a zerk fitting. This was maintained for three (3) days with an occasional injection of grease until the handle on the grease gun was hard to push. Eventually, some of the transmission fluid started to seep from around the piston. Next, the engine was repositioned into the horizontal position. Now, my problems started. Since the transmission fluid was allowed to contact the valves, it began to leak from the muffler and the mixer assembly.

The muffler was removed and 1¼" pipe plug was inserted into the exhaust port. The intake mixer assembly was removed and replace with a blank plate. This stop the valve leakage until the thicker grease displaced the lighter transmission fluid. A small amount of grease leakage was experienced around the valve stems.

The hopper was filled with hot water and grease pressure was constantly maintained with a manual grease gun in this configuration for several days. The rod bearing was loosened and rocking motion via the flywheels was applied several times. This rocking action didn't seem to help.

Eventually, the application of hot water in the hopper and keeping the cylinder pressurized with a manual grease gun forced the piston to move slightly. Next the rod was completely disconnected from the crankshaft. As the grease gun was pumped, the piston moved very little. Subsequently, a power gun was used and the piston continued its journey out of the cylinder.

Every thing proceeded as expected until the skirt of the piston was about an inch out of the block when grease oozed out of the drip oiler pipe. A ¼" pipe plug was inserted and the piston removal process continued until the piston was completely out. The use of the power grease gun (after observation of piston movement) saved a considerable amount of time.

As the piston was coming out, there was some grease leakage observed between the piston and cylinder. Inspection of the piston after removal showed that gap of the three rings weren't staggered but the ring gaps were aligned in a straight line.

Now, the grease has to be removed from the cylinder. Next, the head will have to be removed, inspected, and the valves checked. Of course, the cylinder will be honed before reassembly.

Francis Maciel
Santa Maria, California 

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Subject: Re: Sattley 1½ HP Restoration Status
Date: Sat, 23 Sep 2000 22:22:00 -0400
From: John Culp 

|There was a big discussion on here some time ago about piston ring gaps and |that they tend to line up after a while. Apparently rings rotate during |running.

They do. When the ring gaps line up, that means that the bore has become egg-shaped in cross section. The gaps line up on the "pointy" side of the ovoid, where they have the most room to expand. In a perfectly round bore, even though the rings slowly rotate (or not so slowly in a newly honed bore), they stay randomly misaligned.
John